The present invention relates to a photograph printing method, and more particularly to a photograph printing method in which a print exposure amount is determined in accordance with object information recorded on a recording medium, such as photographic film, when taking an object image, the object information including brightness information, average color information, scene classification information, and the like, of an object (subject).
In making photoprints, the print exposure amount for each of three primary colors (red, green, and blue) is determined in accordance with a measured average density of the overall area of a frame image recorded on a photograph film. This exposure control is called an LATD (Large Area Transmittance Density) method, by which the print exposure amount for each color is determined so as to obtain a finished photoprint of which integration of the three primary colors yields an appropriate grey scale tone.
With this LATD method, a frame having a scene of one-sided density or color results in an improperly finished principal image. Therefore, a print exposure amount determined by the LATD method is corrected by classifying a frame scene in accordance with characteristic values such as maximum and minimum transmittance densities, and calculating a correction amount by using a calculation equation prepared for each scene.
A camera shutter and aperture are controlled in accordance with object brightness, so that an image of the object is recorded on the photographic film with proper density. The density of an image recorded on photographic film does not allow discrimination among photographing times, such as night, evening, and daytime, or among photographing locations, such as outdoor and indoor. For instance, a scene taken in the setting sun is judged as a rear light scene, so as to reduce a print exposure amount. As a result, such a scene cannot be reproduced properly. It also is not possible to discriminate between a scene with fireworks and an underexposed scene, resulting in improper printing of a scene with fireworks. A scene with a dark background, such as a scene taken with a flash, results in under-exposure of the principal object.
The color of an image recorded in a photographic film may change greatly depending upon film age, object condition, and photographing condition (e.g. type of illuminating light, reciprocity law failure of photographic film). Depending on these conditions, a frame image can result in a photoprint having poor color balance if print exposure control is conducted by the LATD method. The color of an image recorded on photographic film also changes with the coloring property and the color of its base.
To deal with the foregoing problem, there is a known method in which color is corrected in accordance with film type information provided prior to printing. In addition, in view of the above-described various problems, there is a proposed camera of the type in which a property of illuminating light also is taken as a spot image in an area near a frame (Japanese Patent Laid-open Publication No. 51-117632). The spot image recorded in a photographic film is subjected to photometry to determine a print exposure amount. Another method also has been proposed (in Japanese Patent Laid-open Publication No. 52-13333) in which light entering through an optical wedge from a main illuminating light source illuminating an object is taken in an area between frames, the density in this exposed area is measured, and a print exposure amount for each of the three colors is determined so that the area will be reproduced as an achromatic color or reference color on a photosensitive material.
The above methods both detect a scene illuminating light recorded on the photographic film and determine a print exposure amount such that the illuminating light exposed area on a negative film will be reproduced as a grey color on a photosensitive material. However, it is difficult for these methods to record only the scene illuminating light on photographic film without the influence of light reflected from an object. For instance, for a scene where a human figure in red clothing stands on a lawn and for a scene with solid colors such as a sea or a mountain under a clear sky, the color of an object differs from an original color, if a photoprint is made by using a print exposure amount determined such that the illuminating light recorded in a photographic film will become a grey color on a photosensitive material.